Survival data for small cell lung cancer (SCLC) is typically reported from clinical trials or institutional series that include patients fit enough to meet treatment criteria. The denominator of all SCLC patients from which the treated population is derived is rarely reported and the impact of new treatment strategies on population-based outcomes is difficult to measure. The British Columbia Cancer Agency (BCCA) is a single centralized agency that coordinates cancer treatment services in the province and develops and circulates province-wide treatment guidelines. All SCLC cases diagnosed in BC in 1990 and 1995 (n=331 and 297, respectively) were identified. These 2 years were chosen specifically to examine the impact of a change in practice guidelines from consolidative to early concurrent thoracic radiation (RT) for patients with limited stage disease. Demographic, staging, treatment, and outcome details were obtained for 100% of cases. A total of 628 patients were reviewed, 207 with limited stage disease (LSCLC) and 407 with extensive stage disease (ESCLC); 14 cases diagnosed at post-mortem were excluded. Of the 207 patients with LSCLC disease, 170 (82%) received chemotherapy, and 138 (81%) of those that received chemotherapy also received thoracic radiation. A similar proportion (73 and 70%) of LSCLC patients received thoracic RT in both years but more patients in 1995 received early concurrent versus consolidative thoracic RT compared to those treated in 1990 (64% versus 17%, respectively, P=0.001). Of the 407 patients with ESCLC, 71% received chemotherapy. The median overall survival for all patients was 7 months. Patients with LSCLC who received any chemotherapy had a median survival of 14.3 months (26.9 and 9.9% for 2- and 5-year survival, respectively). Patients with LSCLC who received chemotherapy plus thoracic RT had a median survival of 15.1 months (32 and 12% for 2- and 5-year survival, respectively). Early concurrent thoracic RT in LSCLC was associated with an improved 5-year survival from 9.6 to 16.3% (P=0.91). Patients with ESCLC who received any chemotherapy had a median survival of 8.4 months (7.3 and 2.3% for 2- and 5-year survival, respectively). Standard treatment guidelines generated population-based survival outcomes that are similar to published clinical trials.